What is an ERV and why do we need one?

Maintaining a healthy indoor environment requires adequate ventilation. Our Energy Recovery Ventilation Kits are the solution to provide optimal ventilation for passive homes, healthy homes and high-performance homes.

 

The Importance of Energy Recovery Ventilators (ERVs) and Heat Recover Ventilators (HRVs):

Modern, energy-efficient homes with tightly sealed environments necessitate a dedicated ventilation system to prevent the accumulation of stale air and pollutants. Not only can excessive CO2 cause drowsiness, headaches and reduced concentration, the buildup of volatile organic compounds (VOCs), carbon monoxide (CO), carbon dioxide (CO2), Allergens and other contaminants can contribute to "sick building syndrome" and respiratory conditions.

 

Relying solely on heating and air conditioning (HVAC) systems for ventilation can result in excessive energy consumption and inefficient air circulation and in fact, the "V" is missing in these systems. The heating/cooling system just recycles the air in the home unless an ERV/HRV is included, bringing the "V" into the house. An ERV system addresses these issues by effectively removing pollutants and introducing fresh air for enhanced indoor air quality, achieving a complete air exchange approximately every 3 ½ hours to ensure a safe and healthy indoor atmosphere while minimizing HVAC usage combined with the low watt draw of an ERV/HRV.

 

Key Functions of ERVs and HRVs:

ERVs and HRVs enhance indoor air quality in an energy efficient manner, creating a whole house air exchange environment while regulating moisture levels (ERVs only) and recovering heat from exhaust air to preheat incoming fresh air.

 

Comparison of HRV and ERV Systems:

  • Both systems recover heat from exhaust air to preheat incoming fresh air.
  • ERVs are great for high humidity or fluctuating season climates. During cold dry weather ERVs help to retain moisture indoors, preventing the air from becoming overly dry which can lead to irritation, dry skin and damage to wood floors and furniture.  ERVs are also ideal for humid or temperate climates where excessive moisture can lead to mold or mildew.
  • HRV's are typically only used in colder, drier climates with no humidity management ability where heat recovery is more necessary.

Traditional Ventilation Methods:

  • Exhaust Fans: These fans, such as those used in bathrooms, remove air indiscriminately, often creating an imbalance and negative pressure that draws air from other areas of the house. This uncontrolled airflow can lead to drafts and the transfer of odors and heat throughout the building.
  • Supply Air: Traditionally provided by HVAC systems, again no "V" or fresh air, the airflow rate is typically one ton of air per 500 square feet of floor space for a traditional home.
    • An airtight and better insulated home with an independent ERV system allows the HVAC system to operate more efficiently, requiring only one ton of air per 2,500 to 3,000 square feet of floor space and so greatly reducing energy consumption.

Balanced Ventilation:

ERV systems, especially when paired with a manifold kit, provide targeted air distribution for optimal air exchange. Exhaust air is drawn from areas such as bathrooms, kitchens, laundry rooms, A/V rooms, and gyms, while fresh air is supplied to bedrooms, living areas, home offices and gyms. This balanced approach optimizes the efficiency of the HVAC system and ensures balanced airflow throughout a well-insulated building. The manifold kit is key to a balanced system, and our product offers a verifiable and cost effective solution. Our manifolds are manufactured in the USA using proven materials and best practices, featuring a triple seal for long-term durability.

Modernizing for Efficiency:

  • Standard HVAC systems are typically designed to supply one ton of air per 500 square.
  • A common practice is to integrate ERVs into existing HVAC systems. However, this still does not solve for the power inefficiencies nor for the unbalanced air exchange environment because this method is not targeted nor measurable.
  • Installing an ERV as a separate, standalone system optimizes HVAC operation, leading to significant energy savings. In a passive house, the standalone ERV can recover up to 80% of the energy in exhaust air, allowing the HVAC system to operate at significantly reduced capacity (e.g., one ton per 2.500-3,000 square). In regions like Southern California, even without fully passive construction, significant energy cost savings can be realized through reduced heating and cooling loads, coupled with balanced airflow for healthy air exchange.
  • Smart home system integration: Modern ERVs can be controlled via smartphone apps and home automation systems allowing for automatic adjustments based on indoor and outdoor conditions, scheduling, real-time air quality monitoring, and remote operation. This scheduling can also be integrated with HVAC systems for improved performance and reduced load, extending the HVAC lifespan and offering additional cost savings.

Four Key Requirements for a Passive House:

  1. Airtight construction (now required by code)
  2. High levels of insulation, including high-performance windows
  3. Balanced ventilation
  4. Optimized solar orientation

(The first three requirements are essential for any energy-efficient home)

 

How do we achieve Balanced Air-Flow?

  • Stale air is extracted from bathrooms, kitchens, laundry rooms, A/V rooms, and gyms
  • Fresh air is supplied to bedrooms, living areas, offices, and gyms
  • In addition to the filters inside of the ERV/HRV, a filter box can be added to the intake for pre-filtering fresh air.
  • Fresh air filters can accommodate standard MERV filters (8, 11, and 13)
  • An optional exhaust filter, such as a carbon filter, can be used to trap outgoing odors.
  • ERVs are ideal for the greenhouse, providing fresh air 24/7.
  • Filter changes are recommended every 3-6 months and the energy/moisture exchange cores should be cleaned annually.

 

What does an ERV do?

The ERV system not only has fans to exchange the air in the house every 3 ½ hours (depending on settings) but also utilizes the heat from the exhaust air to preheat the incoming fresh air, typically achieving a minimum 60% heat transfer rate.

 

 

The Advantage of Our Ventilation Kits:

Our Ventilation Kits are designed for targeted ventilation implementation, ensuring accuracy and efficiency from the outset. This is crucial for cost-effective project completion. Critically, our system enables measurable and adjustable airflow for each room.

Our Founder, Scott Kelly, has been involved with Passive House and evolving Net Zero building codes since 2010. While ERVs are often sold as standalone units, sometimes accompanied by basic diagrams, they frequently lack comprehensive installation guidance. This leaves contractors and DIYers to independently determine the necessary components, optimal placement of air outlets and inlets, ductwork routing, and proper inflow/outflow connections.

Through extensive observation and a decade of installing European systems, Scott recognized the pervasive inefficiencies in ventilation ducting installations. In response, he developed this cost-effective kit to simplify the process and eliminate common installation errors. The kit minimizes the risk of incorrect installations and costly rework, thereby protecting contractors' margins and making ERV installation more accessible to DIYers. Our Kits are made to pair with any brand of ERV or HRV.